Characterization of a family 5 glycoside hydrolase isolated from the outer membrane of cellulolytic Cytophaga hutchinsonii
Characterization of a family 5 glycoside hydrolase isolated from the outer membrane of cellulolytic Cytophaga hutchinsonii
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从纤维素分解细胞哈钦森噬菌体外膜分离的家族 5 糖苷水解酶的表征
DOI：
10.1007/s00253-012-4259-x
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发表时间：
2013-05
影响因子：
5
通讯作者：
Liu, Weifeng
中科院分区：
文献类型：
--
作者：
Bi, Yanlin;Zhang, Weixin;Chen, Guanjun;Liu, Weifeng
Cytophaga hutchinsonii是一种丰富的好氧纤维素分解细菌，以接触依赖的方式快速分解结晶纤维素。本文对C.然而，Hutchinsonii在纤维素消化中是未知。本研究从大肠杆菌外膜中分离到一种内切葡聚糖酶，命名为ChCel5A，属于糖苷水解酶家族5（GH5）。哈钦森氏菌ChCel5A的催化结构域表现出典型的内切葡聚糖酶活性，能够水解不溶性纤维素，纤维二糖和纤维三糖作为主要的消化产物。定点诱变鉴定了ChCle 5A中的两个芳香族氨基酸，W61和W308，其显著降低了其对滤纸的水解活性，而仅引起羧甲基纤维素酶（CMCase）活性的轻微降低。编码ChCel5A的chu_1107的破坏对所得突变株的纤维素生长参数没有引起剧烈影响，完整细胞的特异性CMCase活性的降低可忽略不计。目的基因失活能力的证明。hutchinsonii提供了一个机会，以提高其有效利用纤维素的机制的细节的理解。
Cytophaga hutchinsonii is an abundant aerobic cellulolytic bacterium that rapidly digests crystalline cellulose in a contact-dependent manner. The different roles of various predicted glycoside hydrolases and the detailed mechanism used by C. hutchinsonii in cellulose digestion are, however, not known. In this study, an endoglucanase belonging to glycoside hydrolase family 5 (GH5) named as ChCel5A was isolated from the outer membrane of C. hutchinsonii. The catalytic domain of ChCel5A exhibited typical endoglucanase activity and was capable of hydrolyzing insoluble cellulose with cellobiose and cellotriose as the predominant digestion products. Site-directed mutagenesis identified two aromatic amino acids in ChCle5A, W61 and W308, that dramatically decreased its hydrolytic activity toward filter paper while causing only a slight decrease in carboxymethylcellulase (CMCase) activity. Disruption of chu_1107 encoding ChCel5A caused no drastic effect on the growth parameters on cellulose for the resulting mutant strain with negligible reduction in the specific CMCase activities for intact cells. The demonstration of targeted gene inactivation capability for C. hutchinsonii has provided an opportunity to improve understanding of the details of the mechanism underlying its efficient utilization of cellulose.
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影响因子：
6.2
作者：
Zhang, YHP;Lynd, LR
通讯作者：
Lynd, LR
影响因子：
--
作者：
Stanier, RY
通讯作者：
Stanier, RY
影响因子：
--
作者：
R. Stanier
通讯作者：
R. Stanier
DOI：
10.1042/bj0320031
发表时间：
1938
期刊：
The Biochemical journal
影响因子：
--
作者：
Ernest Walker;Frederick Lloyd Warren
通讯作者：
Ernest Walker;Frederick Lloyd Warren
影响因子：
5.6
作者：
Chapon, V;Czjzek, M;Barras, F
通讯作者：
Barras, F